Diabetes and Insulin Pumps
Medical treatment of several illnesses/conditions requires continuous drug infusion into various body compartments, for example, through subcutaneous and intra-venous injections. Patient suffering from Diabetes mellitus (DM), for example, require the administration of varying amounts of insulin throughout the day to control their blood glucose levels. In recent years, ambulatory portable insulin infusion pumps have emerged as an alternative to multiple daily syringe injections of insulin, initially for Type 1 diabetes patients (see, for example, Diabetes Medicine 2006; 23(2):141-7) and subsequently for Type 2 (see, for example, Diabetes Metab 2007 Apr. 30, Diabetes Obes Metab 2007 Jun. 26). Such pumps, which deliver insulin at a continuous and/or periodic basal rates as well as in bolus volumes, were developed to liberate patients from having to perform repeated self-administered injections, and to enable them to maintain a near-normal daily routine. Both basal and bolus volumes have to be delivered in substantially precise doses, according to individual prescription, because an overdose or under-dose of insulin could be fatal.
Insulin Pump Generations
The first generation of portable insulin pumps included “pager like” devices each having a reservoir contained within a housing. A long tube delivered insulin from the pump attached to a patient's belt to a remote insertion site. The reservoir, delivery tube and the hypodermic cannula together constituted an “infusion set”. With these first-generation devices it is recommended that they be replaced every 2-3 days to avoid local infection at the cannula insertion site. Such devices are disclosed, for example, in U.S. Pat. Nos. 3,631,847 3,771,694, 4,657,486 4,544,369, the contents of all of which are hereby incorporated by reference in their entireties. These devices represent a significant improvement over multiple daily injections, but tend to be relatively large in size and in weight. Additionally, these devices generally require long tubing, making the device somewhat bulky and cumbersome to wear and carry. One reason for the relatively large weight and size of these devices is the large sized batteries (e.g., of AA or AAA-type) required for meeting the high energy demand of the motor, screen, alarms, and other power consuming components of the devices.
The bulkiness of first generational insulin pump devices (in part because of the long tubing used) harms the devices popularity with many diabetic insulin users because these devices disturb users' regular activities, e.g., sports activities, like swimming.
To avoid the tubing limitation, a new concept for a second generation was proposed. The new concept was based on a remote controlled skin adherable device with a housing having a bottom surface adapted for contact with the patient's skin, with a reservoir contained within the housing, and with an injection needle adapted to be in fluid communication with the reservoir. These skin securable (e.g., adherable) devices are designed to be replaced every 2-3 days, similarly to the currently available pump infusion sets. However, many patients prefer to extend this period until reservoir emptying. The second-generation paradigm is described, for example, in U.S. Pat. Nos. 4,498,843, 5,957,895, 6,589,229, 6,740,059, 6,723,072, and 6,485,461, the contents of all of which are hereby incorporated by reference in their entireties. Second-generation skin securable devices generally require that the entirety of the devices be disposed-of every 3 days, or so, thus resulting in some of the more expensive components (e.g., electronics, driving mechanism) being discarded. Additionally, a remote controlled skin securable device tends to be heavy and bulky, thus creating an impediment for maintaining daily activity. Here too, one reason for the large size and heavy weight of second generation devices is their sizes and the relatively large number of batteries they each hold to supply energy to the devices' motors, alarms, communication mechanisms used to maintain a communication link between the skin securable devices and the remote controls, etc. In U.S. Pat. No. 7,144,384, the content of which is hereby incorporated by reference in its entirety, a skin adherable device is disclosed: In one embodiment, a large portion of the device's volume is occupied by four (4) Silver-Oxide button batteries positioned perpendicularly to the longitudinal axis of the device, making the device thick (18 mm) and bulky. Moreover, the heavy and bulky batteries used with such insulin pump devices typically last for only 3 days, thus requiring the user to discarded the expensive device typically every 3 days.
A third generation (3rd gen.) skin adherable device was developed to avoid the price constraints associated with earlier generations and to extend patient customization. An example of such a device is described in previously filed patent application Ser. No. 11/397,115 and PCT International Application No. PCT/IL06/001276, owned by Medingo, the contents of both these applications is hereby incorporated by reference in their entireties. A third generation device includes a remote control unit and a skin securable (e.g., adherable) patch unit that includes two parts:                A first portion (e.g., a “reusable part”) containing a metering portion, electronics, and other relatively expensive components.        A second portion (e.g., “disposable part”) containing the reservoir retaining therapeutic fluid (e.g., insulin) and, in some embodiments, batteries. The disposable part also includes a tube to deliver the fluid from the reservoir to an outlet port that contains a connecting lumen.        
The third-generation device concept provides a cost-effective skin adherable infusion device and enables diverse usage with different reservoir sizes, different needle and cannula types, etc.
Continuous Glucose Monitors (CGM) and Closed Loop System
Continuous sensing of bodily analytes within the interstitial fluid of the subcutaneous (SC) tissue is described, for example, in U.S. Pat. Nos. 5,390,671, 5,391,250, 5,482,473, 5,299,571, and 6,565,509, the contents of all of which are hereby incorporated by reference in their entireties. These sensing devices each includes, in some embodiments, a subcutaneous probe and a sensing unit that contains a processing unit and energy supply. In previously filed U.S. patent application Ser. No. 11/706,606, entitled “Systems and methods for sensing analyte and dispensing therapeutic fluid”, the content of which is hereby incorporated by reference in its entirety, an insulin dispenser and a glucose sensor are disclosed that are contained within one skin adhered unit that is provided with a reusable part and a disposable part. In such a dual function device, a closed loop system may be implemented where insulin is dispenses based on, at least in part, sensed glucose levels (artificial pancreas). In some embodiments, the batteries reside in the reusable part of this dual unit.
Pump and Sensors Batteries Recharging
A first generation infusion pump powered by rechargeable batteries is described in U.S. Pat. No. 5,225,763 to Krohn et al., the content of which is hereby incorporated by reference in its entirety. The batteries can be recharged by a base unit connected to AC power. Under some circumstances, the pump operation of such a device might have to be suspended during charging. This may be unacceptable for insulin pump users because stopping the delivery of insulin may be detrimental to the users' health.
Use of rechargeable batteries in second generation skin adherable pumps is of less importance because the entire device is generally disposed-of every few days (insulin pump are usually disposed-of every 2-3 days). Moreover, batteries recharging cannot be done during operation because the device is connected to the user's body.
In third generation devices, the skin-securable units, each comprises a reusable part and a disposable part. If the battery(ies) resides in the reusable part it can be recharged. A patient may use two reusable parts so that when one reusable part is operating the second one is being recharged.
In a continuous glucose monitor (CGM) or in a CGM with insulin dispenser that includes a reusable part and a disposable part, batteries can reside in the reusable part and be recharged when another reusable part is operating.
Pumps and Sensors Data Downloading
Pump log file, recording and maintaining information regarding insulin delivery, have to periodically be downloaded to a PC to be used, for example, in delivery programs tailoring.
A first generation insulin pump enables data downloading during pump operation is described, for example, in U.S. Pat. No. 5,376,070, the content of which is hereby incorporated by reference in its entirety. The pump may be connected to a communication station and data may be transferred from the pump using, for example, optical coupling. In embodiments of such apparatus, the user is tied, in effect, to the communication station to avoid drug delivery interruption.
Data downloading in second generation pumps may be performed wirelessly to a remote control. In the event of remote control loss or malfunction, the data stored in the pump and stored data in the remote control may be lost.
In third generation insulin pumps, having reusable and disposable parts, data transfer from one reusable part can be done while another reusable part is operating.